On paper, it doesn’t look too promising. A 24-year-old, piston-port, two-stroke engine of European origins, designed to potter about and pull from nowhere in the rev-range at the riders behest. No reed valves, power valves, ignition advance or other techie items deemed necessary for a stroker to do such work, surely this cannot be possible? Well, within seconds of actually starting the Sherpa T, selecting first gear, and getting going on it you begin to realise it is even better than that. In practise, the Bultaco engine is a real donkey that carburates impressively and pulls even more so.
The 1982 250cc 198B model used for the test, proved to be a sprightly performer and also an altruistic one, as it did its very best to hide my ham fisted trials riding technique. Being one of the very last Sherpa T’s ever made, it represents the pinnacle of the types design and development. This is the machine developed by the Finnish rider Yrjo Vesterinen and, as a tribute to his three world titles on the type, is adorned in blue and white, the colours of his national flag.
Thanks to a new CDI ignition, the Sherpa starts up without complaint. The kick-starter is a little awkward to get used to, it being on the “wrong side”, thankfully, once running, nothing, except a dead stop in gear, will stall the engine, so using it is infrequent. From the word go, control is easily gained on this narrow, light, but clearly powerful, machine. The two-stroke engine sounds familiar but certainly doesn’t feel that way; it could easily be a thumping four stroke such is its ability to dig down deep in the rev range. The large flywheel rotor helps the engine keep going when the revs drop into treble figures, and below, making the engine perform more like a diesel than a stroker. Clever porting too has the power delivery absolutely spot on, maximum torque is produced a shade under the max horse power, at 4000 and 5500rpm respectively, enabling a sharp hit of power capable of projecting you and the bike up and over some amazingly sized obstacles. It is difficult to imagine how much more powerful and agile the 350 Sherpa is than the 250, with around a third more power and torque at similar rev ranges and yet weighing the same, it must be a real handful.
Despite the stood up riding stance and obvious low speeds involved in the sport of trials, the muscles and strength required is no less than any other form of motorsport. By shifting your weight in anticipation of the next obstacle the Sherpa will gladly tackle it, a slight whiff of gas has the front end in the air, or the rear end sliding around stuff accordingly. The Bultaco journeys on whether or not you are totally aware of the exact mechanics of the progress and sometimes it leaves you wondering just how much of a part you are playing in the proceedings. This ability to get itself out of a hole or up a steep incline is perfectly matched to the chassis agility and lithe shape. With a turning circle seemingly tighter than its own length the bars can be turned so far around you think it is going to disappear inside itself.
It is difficult to imagine what would stop this bike in its tracks, I certainly wouldn’t want to be riding it when it came along that’s for sure because it would be big and very high. It is light well-balanced and tremendous fun to ride, requiring only a good throttle technique and rider balance to get the job done; the bike appears to do the rest.
In 1944, Pedro Permanyer and Francisco Bulto formed the Spanish Montesa Company, their aim was the building of small capacity two stroke machinery for all forms of motorcycle competition, both on and off road. They met with considerable success and Montesa machines were soon on the rostrum at the TT and other notable races. A decision by the Montesa board in 1958, to quit its involvement in competition saw Bulto, a racing fan throughout his life, leave to pursue his own ideas. Soon after Bulto’s departure from the Montesa concern he had found premises in Barcelona and, with the aid of other former Montesa employees, created the Bultaco brand. The first model was the Tralla 101, a single-cylinder 125cc two-stroke capable of producing 12bhp and over 70mph. They sold over 1000 of these in their first year of production, the sales being given a considerable boost by their first major race win, a race in which they competed against the factory MV and the Desmodromic Ducati.
Within two years Bultaco had produced the 196cc Sherpa N and this in turn led to an interest in the uniquely British past time of trials riding. Bulto entered a team into the 1964 Scottish and International six days trials, although not successful they did get to see the master of the art at the time, Sammy Miller, in action. Miller was the factory rider for the UK Ariel company and was one of the worlds leading trials riders during the sixties. Over the years he had developed the four-stroke Ariel into a thoroughbred trials machine the like of which had not previously existed. He lightened the chassis and steepened the steering head to make it supremely agile and able to tackle obstacles previously thought to be unrideable.
The Miller/Ariel combination became virtually unbeatable and his obvious talent for machine development did not go unnoticed. Sammy was invited to Spain by Bulto to look at the Sherpa, he takes up the story;
“I was the first man to get Spain and Europe into English trials. Senor Bulto, the founder of Bultaco, was a great road-racing and trials enthusiast and we enjoyed a great relationship. We built the first Sherpa in just 12 days, including a re-designed engine (72 x 60 bore/stroke), timing, internal balance, ignition and gearbox to a set of ratios more suitable to trials.”
“Betor made trials forks and spokes to my specification and it was a winner straight off. But like leaving Belfast to go to the Ariel factory in Birmingham, there was no going back; I had burnt my bridges. With Bultaco’s success, Ossa and Montesa joined the band-wagon, it’s always easy to copy.”
In typical style Miller’s Ariel contract ended on a Saturday late in 1964 and he won the British experts trial for the brand on that day. The very next day he travelled to the Cotswolds to take part in, and subsequently win, the King’s Norton club trial with the new Bultaco, a new era had begun. Gone was the “thump thump” of the British single to be replaced by the smell of Castrol R and the “ring ding” of the two-stroke.
Sammy and the Sherpa T reigned supreme, taking the UK title for five years between 1965 and 1969 and also, the forerunner to the world championship, the European crown in 1968 and 1970. Not only was he and the Sherpa T totally dominant, it was the first time a two-stroke machine had ever won in major competition since the beginnings of the sport 54 years earlier. Sammy constantly updated, revised and modified his machines, sometimes to the companies chagrin, but always with success in mind. Just like he had done with the Ariel, Miller took the original Model 10 design on to be a machine capable of taking on the world. Success continued into the 70’s at the very highest levels of competition albeit with different riders on board as Sammy made way for the likes of Martin Lampkin and Malcolm Rathmell, the former taking the inaugural world title for Bultaco in 1975. For 1972, the original 250 was given a boost in power and torque, simply by increasing the bore from 72mm to 83.2mm to create the 326.03cc machine better known as the 350 Sherpa T. 1975 saw the first ever World Trials championship and Bultaco and Lampkin carried on the winning ways by taking the first ever title. Bultaco held on to the crown for the rest of the 70’s, further consolidating the types amazing ability and seemingly unstoppable success.
Bultaco didn’t make it very far into the 80’s. Spain’s political turmoil and the industrial action suffered by the country as a whole saw the company struggling to put machines out into the market place. Bultaco’s last world champion, America Bernie Schreiber, brought with him a new style of trials riding. Rather than the old way of gently, and slowly, negotiating each obstacle, Schreiber employed the stop-start method more common today. This was no less methodical in its technique but it did require a new, lighter and more agile, type of machine, akin to the lightly sprung and long travel suspension models we see in today’s competition.
The Japanese where catching up with Bultaco on the trials scene and by the mid 80’s Yamaha had surpassed it, their new TY250 bore little resemblance to a traditional trials machine, featuring a low down, minimalist chassis and monoshock suspension along with a torque reed valve engine, enabling incredible feats of climbing even from a standstill.
Honda made great strides too, having invested heavily in the Montesa concern while Bultaco was left to its own devices. Bultaco had been in financial difficulties since the late 70s and it was only a matter of time before the doors closed for the final time in 1982. They had clinched no less than 4 European titles, 5 world, 11 Spanish national championships and 11 UK ones too.
The first Sherpa 250cc Model 10 appeared. 1275 were produced over the next 3 years. Sammy miller won first time out on the Bultaco.
A new five-speed gearbox and a few detail changes created the model 27.
The bore was increased to create the first 350 Sherpa T (actually a 326cc machine)
Bultaco win the very first world trials championship and continue to do so for the next five years. The capacity of the 250 was reduced to 237.55cc, from 244.29cc, to avoid a heavy tax burden in some European countries.
October that year saw the introduction of the new “interrupted” frame. Basically the down tubes ended at the front of the engine instead of looping all the way around to the swing arm point. This gave an extra inch or so ground clearance.
Saw the final incarnation of the Sherpa T concept as the 326cc
engine is bored out to 340.47cc and a the gearbox gains an extra gear, making it a six speed box.
Notable Bultaco Sherpa T successes
1968 – Sammy Miller UK
1970 – Sammy Miller UK
1973 – Martin Lampkin UK
1974 – Malcolm Rathmell UK
1975 – Martin Lampkin UK
1976 – Yrjo Vesterinen Fin
1977 – Yrjo Vesterinen Fin
1978 – Yrjo Vesterinen Fin
1979 – Bernie Schreiber US
1965 – Sammy Miller
1966 – Sammy Miller
1967 – Sammy Miller
1968 – Sammy Miller
1969 – Sammy Miller
1972 – Malcolm Rathmell
1973 – Martin Lampkin
1974 – Malcolm Rathmell
1978 – Martin Lampkin
1982 – Yrjo Vesterinen
Bultaco Sherpa 250 198B Specifications
- Engine – single-cylinder air-cooled piston-ported two-stroke
- Capacity – 237.55cc
- Bore & stroke – 71mm x 60mm
- Compression Ratio – 9:1
- Carburetion – 28mm Amal
- Max Power – 14.1bhp @ 5500rpm
- Torque – 14.5 ft-lb@ 4000rpm
- Ignition – contact breaker
- Transmission – 5-speed, wet clutch, chain final drive
- Frame – interrupted steel tube
- Suspension – 35mm telescopic forks twin rear shock
- Wheels – 2.75 x 21 4.00 x 18
- Brakes – 125mm single leading shoe front and rear
- Wheelbase – 1315mm
- Weight – 92.5kgs
- Fuel capacity – 6 litres
- Top speed – N/A
Bultaco Sherpa T Gallery
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